The performance required for bicycle tires significantly differs depending on the driving environment and purpose. For example, lightweight is considered essential for tires of bicycles such as road bikes or the like, and it has been known to aim at reducing vibration by increasing air volume.
In order to satisfy the air volume sufficient for those bicycle tires including road bike tires, it is necessary to prevent rim detachment. The air volume in the bicycle tires including road bike tires is preferably 1500 kPa or more in accordance with the water pressure test for bicycle tire rim running-off resistance described in JIS K 6302.
Hence, for the purpose of reducing weight of a bicycle tire, it is known that a high-strength organic fiber is used as a bead fiber to be used in a bead portion which is a mating portion between a bicycle tire and a rim.
For example, Patent Document 1 proposes that a high-strength wholly aromatic polyester fiber is used as a bead fiber which is lightweight and easy to handle.
In Patent Document 2, the bead fiber that may be used includes a para-aramid fiber such as “Technora” (registered trademark) produced by Teijin Limited and “Kevlar” (registered trademark) produced by DuPont; high-strength polyethylene, and the like. Patent Document 2 proposes that of these, a para-aramid fiber is preferred.